In recent years, air conditioners, which provide comfortable living and working spaces, have become equipments essential not only for office buildings and residential houses, but also for carriage and transport vehicles such as automobiles, train cars, ships and vessels and airplanes. In general, the environment making use of an air conditioner is highly airtight so as to enhance an energy efficiency. Accordingly, if a human being continues to work in such an airtight space, the working efficiency lowers owing to the shortage of oxygen. Especially, with carriage and transport vehicles, there may be presented a problem on safety such as of causing drowsiness. Although the opening of window makes it possible to prevent an oxygen concentration from lowering, such opening will lead to an energy loss and permit pollen, yellow sand, dust to enter, thereby impeding the comfortable environment. Under such conditions, there have been developed air conditioners making use of an oxygen enriching film capable of selectively passing oxygen, with failure in realizing still a satisfactory performance.
Organopolysiloxanes are known as a material whose oxygen permeability is excellent. However, organopolysiloxanes per se are low in mechanical strength, presenting a problem in practical applications. To overcome this problem, there have been proposed copolymers with polycarbonates (Patent Document 1: JP-B H04-001652) and polysiloxane/aromatic polyamide-based block copolymers (Patent Document 2: JP-A H05-285216). However, these have problems in that not only their preparations are very complicated, but also long-term stability is lacked because of their susceptibility to hydrolysis.
Further, a variety of polymers having an organosilicon substituent have been proposed including, for example, silicon-containing styrene derivatives (Patent Document 3: JP-A H04-88004), silicon-containing stilbene derivatives (Patent Document 4: JP-A H08-198881), and silicon-containing celluloses (Patent Document 5: JP-A 2001-79375). Those polymers that are satisfactory with respect to oxygen permeability, thermal stability and mechanical strength have never been obtained yet.
In Patent Document 6 (JP-A 2007-291150), ring-opened polymers of cyclic olefin compounds having an organosiloxane as a pendant, and hydrides thereof, have been proposed. However, these polymers present problems on heat resistance and film strength in most cases, along with a problem in that they lack in long-term stability because of their capability of depolymerization.
With respect to the addition polymerization of cyclic olefin compounds, a number of proposals have ever been made (Patent Documents 7 to 22: JP-A H04-63807 and JP-A H08-198919, JP-A H09-508649, JP 3476466, JP-A H07-196736, WO 199720871, WO 199820394, JP 3801018, WO 2002062859, JP-A 2003-252881, DE-OS 4128932, JP-A 2007-77252 and JP-A 2007-70337, JP 4075789, WO 2007069518, and JP-A 2008-202003). However, no mention has been made of cyclic olefin-functional siloxanes as a monomer for addition polymerization reaction. As a matter of course, examples of addition polymers actually containing the siloxane as recurring units have never been reported.
In the just-mentioned Patent Documents 7 to 22, cyclic olefin addition polymers have been described in detail with respect to the development to applications for optical and electronic parts while taking particular note of thermal, dynamic, optical and electric properties thereof. Nevertheless, no report has been made on applications focused on the gas permeability.
Recently, addition polymers containing recurring units of cyclic olefin-functional siloxanes in the structure have been reported in Patent Document 23 (JP-A 2009-173824) and Patent Document 24 (JP-A 2009-249610). However, although the polymers set out in these applications exhibit excellent solubility, they do not have both mechanical strength and gas permeability enough to withstand practical applications. Especially, with the polymer proposed in the latter Patent Document 24, when the amount of an organosiloxane pendant imparting gas permeability to the polymer increases, mechanical strength significantly lowers. This is because when cyclic olefin-functional siloxanes are used as a monomer for addition polymerization reaction, there cannot be obtained polymers whose molecular weights are sufficient to ensure mechanical strength, suggesting that the preparation methods set forth in both Patent Documents 23 and 24 have some problems to solve.
The prior art documents are listed below.
Citation ListPatent Document 1:JP-B H04-001652Patent Document 2:JP-A H05-285216Patent Document 3:JP-A H04-88004Patent Document 4:JP-A H08-198881Patent Document 5:JP-A 2001-79375Patent Document 6:JP-A 2007-291150Patent Document 7:JP-A H04-63807Patent Document 8:JP-A H08-198919Patent Document 9:JP-A H09-508649Patent Document 10:JP 3476466Patent Document 11:JP-A H07-196736Patent Document 12:WO 199720871Patent Document 13:WO 199820394Patent Document 14:JP 3801018Patent Document 15:WO 2002062859Patent Document 16:JP-A 2003-252881Patent Document 17:DE-OS 4128932Patent Document 18:JP-A 2007-77252Patent Document 19:JP-A 2007-70337Patent Document 20:JP 4075789Patent Document 21:WO 2007069518Patent Document 22:JP-A 2008-202003Patent Document 23:JP-A 2009-173824Patent Document 24:JP-A 2009-249610Patent Document 25:JP 3534127Patent Document 26:WO 200020472Patent Document 27:US 6455650Patent Document 28:JP-A H05-262821Non-Patent Document 1: Macromol. Symp. 89, 433-442(1995)